How do you put a friend in first position as a private lender?

[Larry K.]

How does this exactly work? What does the agreement look like? What does it say? Do you need an attorney to write it? Does the SEC need to be involved?

Scenario would be a friend and I agree to go in on a deal together. I'd make the offer (no LLC or anything like that). He would fund the money at closing, say 75%LTV of current value, not ARV. I'd pay the balance with my own funds.
I'd manage and pay for the renovation with my own funds. Get the place leased-up. I'd go for a refi. With money from the conventional refi lender I would pay back my friend. He is done and happy. I have a cash-flowing property with some equity (lets hope)

Neither of us are bankers. So how do you set this up?